The traditional light emitting diode (LED) is used as backlight in the display technology. The display technology at present has been developed from backlight into a self-luminescent type including the techniques such as organic light emitting diode (OLED) and micro light emitting diode (Micro LED). Among them, the Micro LED technology, i.e., LED scaling-down and matrix technology, refers to the LED arrays with high-density and micro-size integrated on one chip. The size of Micro LED is scaled down to a micron level, and not only each point of pixel can be controlled by addressing and driven to emit light at single point, but also there are the advantages including high brightness, low power consumption, and ultra-high resolution and color saturation. The OLED is a current-type device, in which the brightness is determined by the amplitude of current flowing through the OLED.